Electric treater with gravity-liquid heat barrier

ABSTRACT

A system for electrically treating emulsions which includes a vessel containing inlet and outlets and an electric field formed by electrodes connected to an external transformer. A rigid conduit extends from the vessel to a closed end containing an entrance bushing connected to the transformer and an electrical conductor extends through the conduit between the entrance bushing and the electrodes. The electrical conductor is supported concentrically and in electrical isolation from the conduit. The conduit has an upright portion extending from the vessel, an intermediate bight portion with an 180* return bend forming a thermal dam, and a downwardly extending portion which connects to the closed end. The downwardly extending portion of the conduit carries a heat exchanger for creating a temperature gradient between the entrance bushing and the interior of the vessel. The liquid within the vessel can be carried at relatively elevated temperatures (e.g., 500*F.) while the entrance bushing remains at relatively low temperatures (e.g., 100*-200* F.). Electrical resolution of emulsions at elevated temperatures for extended periods can be obtained without temperature-induced destruction of the entrance bushing.

FOREIGN PATENTS OR APPLICATIQNS United States Patent 1 1 1 3,719,584 Turner 51 March 6, 1973 ELECTRIC TREATER WITH GRAVITY- Primary ExaminerJohn H. Mack LIQUID HEAT BARRIER Assistant Examiner-T. Tufariello [75] Inventor: Delber W. Turner, Houston, Tex. Att0mey Emll Bednar et [73] Assignee: Petrolite Corporation, St. Louis, [57] ABSTRACT I A system for electrically treating emulsions which in- [22] Filed: July 19, 1971 cludes a vessel containing inlet and outlets and an electric field formed by electrodes connected to an ex- [211 163637 ternal transformer. A rigid conduit extends from the I vessel to a closed end containing an entrance bushing [52] US. Cl. ..204/308, 174/15 BH connected to the transformer and an electrical con- [51] Int. Cl. ..B0ld 13/02, l -l0lb 7/34 ductor extends through the conduit between the en- [58] Field 0! Search ..204/302-308, 186-191; trance bushing and the electrodes. The electrical con- 174/ 15 131-1 ductor is supported concentrically and in electrical isolation from the conduit. The conduit has an upright [56] References Cited portion extending from the vessel, an intermediate bight portion with an 180 return bend forming a ther- UNITED STATES PATENTS mal dam, and a downwardly extending portion which 1,129,466 2 1915 Fortescue ..174/15 BH cmmects the Closed The downwardly extend- 1,766,593 6/1930 B n 17 5 3H ing portion of the conduit carries a heat exchanger for' 1,983,371 12/1934 Hillebrand. ....l74/ 15 BB creating a temperature gradient between the entrance 2,686,827 4/1954 Rofiee ....174/l5 BH bushingand the interior of the vessel. The liquid 2,881,125 1959 at within the vessel can be carried at relatively elevated 2,924,637 2/1960 Turner 304/302 temperatures (e.g., 500F.) while the entrance bushing g i a; remains at relatively low temperatures (e.g., 0 er -----a:""b-" W 3,627,899 12/1971 Moore ..174/15Bl-l 100 200 Elecmcal -res0luuon of emulslons at elevated temperatures for extended periods can be obtained without temperature-induced destruction of the entrance bushing.

57 18 Claims, 3 Drawing Figures PATENTED 61975 SHEET 1 OF 3 I/V. Tar/76v INVENTOR ATTORNEY PATENTED 3,719,584

SHEET EBF 3 l I 3 72 E f 79 I I 77 il i I 76* 74 fie/er 14/. Turner as; I INVENTOR.

K BYIM% ATTORNEY PATENTEB 61975 3,719,584

SHEET 38F 3 I N VENTOR.

ELECTRIC TREATER WITII GRAVITY-LIQUID HEAT BARRIER BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to apparatus for the resolution of emulsions consisting of immiscible external and internal liquid phases. More particularly, the invention relates to the electric treatment of oil-continuous emul- 1 sions containing a dispersed aqueous phase.

2. Description of the Prior Art For many years, electrical fields have been employed in suitable structures for resolving emulsions formed of an internal phase, such as water, caustic or acid etc., and a continuous external hydrocarbon phase, such as crude oil. The emulsions are subjected to a high voltage field which causes the internal phase to coalesce. The term coalesce as used herein refers to the agglomeration of the dispersed internal phase while in-situ in the continuous external phase. In the electric field, sufficiently enlarged particle sizes of the internal phase are created which can readily separate from the external phase by differences in their specific gravities. Many types of electric treaters can be employed in the electrical treatment ofoil-continuous emulsions for removing the dispersed aqueous phase. In conventional treaters, the high voltage applied to electrodes that create the electric field is usually between about 11,000 volts and about 33,000 volts However, the energizing potentials may be above 33,000 volts in some instances. The potential may be provided by either a.c. or dc. power sources. According to conventional practices, voltage gradients established between the electrodes are usually in the range of between about 2.5 kv and about 8.5 kv per inch of spacing therebetween.

Electric treaters may be used solely for dehydrating purposes. The addition of a small amount of dispersed water to the emulsion to be treated will allow the electric treater to be used in desalting. For example, a crude oil stream may be intermixed with between 3 and percent fresh water and then subjected to electrical field treatment which produces an oil-continuous phase relatively free of the dispersed water phase and contaminating salt, brine, etc. Other variations of dehydration-desalting treatments in electric treaters are well known.

Electric treaters have relatively similar constructions. For example, the treater is usually constructed in a pressure-type metal vessel having at least one electrical entrance bushing for conducting the high-voltage energizing potential from an external power source to one or more energized electrodes within the container. The entrance bushing is exposed to the temperature and pressure of the liquid in the electric treater. Each energized electrode is submerged in .the body of the oilcontinuous liquid phase. The emulsion is introduced into the container for movement into the electric field adjacent the energized electrode. The electric field produces coalescence of the dispersed aqueous phase which accumulates as a body of water in the lower portion of the vessel. The resultant oil-continuous phase collects at the upper portion of the vessel and is removed through an oil outlet. The body of water is removed at regulated rates through a water outlet.

The entrance bushing which forms the liquid-tight, electrical interconnection through the metal wall of the vessel between a source of power, (e.g., a transformer) and the energized electrode is an exceptional device. The entrance bushing is an insulator-type device for making an electrical connection under high-potential, elevated temperature and pressure stresses through the metal wall of the containing vessel. For example, the entrance bushing must conduct up to 33 kv or higher potentials into a liquid environment at up to 500 F.

0 and 400 psi or greater of salt-laden crude oils for periods of several years without electrical or mechanical failures.

Various types of entrance bushings have been employed with electrical treaters. Originally, these bushings were formed with insulating materials such as rubber-impregnated silica, porcelain materials, and types of ceramic substances. In relatively recent times, the entrance bushing has been formed of polymer-type insulators such as Teflon plastic materials. Entrance bushings formed of these plastic materials have provided exceptional service in commercial applications on electrical treaters for resolving emulsions. Entrance bushings constructed according to advance state-ofthe-art techniques, such as shown in US. Pat. Nos. 2,881,125, 3,085,128 and 3,303,262, have provided outstanding operational life and safety characteristics. This accomplishment to be appreciated must be viewed against the environment in which these patented entrance bushings have been employed. For example, the desalting of crude oil which began in the late 1930s was usually undertaken at temperatures not over 180 F. In each of the following decades, the temperature and pressure of the crude oil being treated increased greatly. By the late 1960s, the desalting of crude oil was being carried out at temperatures above 300 F. on a routine basis in every day refinery operations. This trend of increasing treating temperatures continues so that in the 1970s, crude oil is desalted at temperatures above 350 F. and will be probably close to 400 F. before the decade ends.

Entrance bushings constructed with Teflon insulating material, have withstood temperatures below 350 F and elevated operating pressures while containing electrical potentials up to 50 kv for extended periods of time in complete safety. However, it will be apparent that these entrance bushings can not suffer (without electrical-mechanical injury) ever increasing operating temperatures, pressures and potentials. For example, the Teflon insulating material has a thermal expansion coefficient several times that of the steel components with which it is associated in the entrance bushing. Additionally, this polymer material has little memory in a cycling of operating temperatures and retains the structure it had at the maximum elevated temperature. Naturally, subjecting an entrance bushing to a cycling of temperatures and pressures eventually creates structural defects in the liquid seals between the polymer material and the metal structural portions. This stress can result in the leakage of liquid, either transformer oil, or the oil being treated, into the internal parts of the entrance bushing. This leakage of liquid may create an electrical are which destroys a portion of a polymer insulator by its conversion into a gas. As a result, there is a loss of insulating quality in the polymer insulating material and will produce a short circuit in the entrance bushing. The sources of power associated with modern electric treaters carry protective devices which reduce the application of power upon such a short-circuit condition. However, the entrance bushing must be replaced in the electrical treater to continue proper operation. Obviously, as the temperature of the liquid ,within the treater increases, the possibility of electrical and mechanical defects in the entrance bushing increase rather rapidly.

Some arrangement is desirable for protecting the entrance'bushing as the liquid temperatures and pressures are increased in operation of electric treaters. A mechanical barrier to isolate the liquid between the electric treater and the entrance bushing is impractical. The barrier is subject to the very same mechanical and severe electrical stresses which lead to dielectric breakdown and short-circuits in the entrance bushing. Coolers may be placed about the entrance bushing at the vessel wall. This structure is relatively impractical because an unending supply of hot liquid within the vessel of the electric heater circulates in contact with the entrance bushing. There is a need for maintaining the entrance bushing in a relatively cool environment compared to the liquids within the electric treater without the problems associated with mechanical barriers and high .capacity coolers etc. The present invention provides a solution to this problem by a novel interconnection of the entrance bushing with the electric treating vessel.

SUMMARY OF THE INVENTION In accordance with this invention, there is provided a system for electrically treating an oil-continuous emulsion containing dispersed phase contaminating substances. The system comprises a vessel containing inlet and outlet means for passing liquids therethrough. An electric field is created within the vessel by electrode means connectable to a source of electrical potential. A conduit extends from the vessel to a closed end containing an entrance bushing connected to the source of electrical potential. The bushing is in liquid communication through the conduit with the interior of the vessel. An electrical conductor extends in electrical isolation within the conduit from the entrance bushing to the electrode means. The conduit contains an upwardly extending portion adjacent the vessel, an intermediate bight portion, and a downwardly extending portion between the bight portion and the closed end containing the entrance bushing. Heat exchanger means are associated with the downwardly extending portion of the conduit for creating a temperature gradient between the entrance bushing and the interior of the vessel.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical cross section of an electric treat- DESCRIPTION OF SPECIFIC EMBODIMENTS Referring now to FIG. 1 of the drawings, there is shown a system of the present invention for electrically treating an emulsion containing dispersed'phase contaminating substances in a continuous external phase. For illustration, the emulsion (liquid) may be considered to be formed of an aqueous dispersed phase within a continuous phase of crude oil. The system includes a vessel 11 which may be a horizontal elongated cylindrical metal tank with closed ends and walls of sufficient structural rigidity to contain the emulsion. The vessel 11 usually is surrounded with a layer of insulation 12 to reduce the loss of heat from the liquid being treated. Electrodes are mounted within the vessel 11 for creating an electric field to resolve the emulsion into the oil-continuous phase and a separated aqueous phase. Generally, the electrodes extend throughout the horizontal extent of the vessel 1 l. v

The electrodes may be formed by any structural arrangement for purposes of the present system. For illustration, an upper grounded electrode 13 is suspended by longitudinal I-beams 17 from hangers 19 connected through support rods 22 to the upper extremity of the vessel 11. The electrode 13 is formed by transverse members 16 upon which longitudinally extending rods 14 are secured. Thus, the electrode 13 is a foraminous arrangement of metallic grounded constituents. An

energized electrode 24 is mounted a short distance belowthe grounded electrode 13. The energized electrode 24 may be constructed similarly to the electrode 13 but with an inverted mounting. More particularly, the electrode 24 is formed by longitudinal extending I- beams 27 supporting transverse members 26. The members 26 support rod electrodes 28 which extend longitudinally in the vessel 11. The electrode 24 is supported on hangers 29 connected through rods 31 to the lower extremities of insulators 33. The upper end of the insulators 33 connect to rods which are secured to the upper extremities of the vessel 11. Thus, the energized electrode 24 is formed of a foraminous metallic structure. The suspension rods 31 traverse the grounded electrode 13 through suitable openings so that the electrode 24 can be energized at an elevated potential relative to the grounded electrode 13.

The electrode 24 is energized to create an electric field within the vessel 11 from a source of electrical potential carried externally of the vessel 11. The source of electrical potential may provide either 3.0. or dc. current at a suitable elevated potential creating an electric field for resolving the emulsion within the vessel 11. In the resolution of crude oil emulsions, the source of electrical potential can be an ac power transformer 36 mounted upon a platform 34 carried upon the vessel 1 1. The transformer 36 connects to primary a.c. feeder lines and produces secondary elevated potentials, (e. g., 1 1-50 kv.), to be applied between the energized electrode 24 and the grounded electrode 13. For example, the secondary winding of the transformer 36 is grounded at one terminal to the vessel 11 and the other terminal connects to the energized electrode 24. The ungrounded terminal of the secondary on the transformer 36 connects by a cable 35 to an entrance bushing 37 which supports one end of an electrical conductor 38 that extends into the interior of the vessel 11. The vessel-interior extremity of the electrical conduc tor 38 is supported upon the grounded electrode 13 by an insulating support 40. An electrical connection between the conductor 38 and the rod 31 is produced by a flexible braid 41. The support 40 may be a cylindrical segment of Teflon tubing secured by J-bolts to the grounded electrode 13. A plate bolted to the end of the conductor 38 is secured to the insulating tubing. Thus, the conductor is held concentrically in electrical isolation within a conduit 39 which extends between the entrance bushing 37 and the electrode 24 within the vessel 11.

The entrance bushing 37 may be constructed in any suitable manner. For example, construction of the bushing 37 in accordance with U.S. Pat. No. 3,303,262 produces a device of accepted utility.

The emulsion enters the vessel 111 through an inlet 42 which carries a distributor 44 with a plurality of horizontally extending arms 43. Openings 45 in the arms 43 distribute the emulsion uniformly beneath the energized electrode 24. Other arrangements of the distributor 44 may be employed, if desired.

During operation of the treater 111, water resolved electrically from the emulsion falls to the lower portions of the vessel 11 and collects into a water body 51. The oil-continuous phase collects in a body 49 in the upper portion of the vessel 11 about the electrodes. Water is removed through the lower outlet 48 from the vessel 11 to maintain an interface 50 between the oil body 49 and the water body 51 at a horizon beneath the energized electrode 24. Generally, the interface 50 is maintained at a horizon adjacent the distributor 44.

The oil-continuous phase is removed from the oil body 49 by an oil outlet 47 having a horizontally extending collector tube with a plurality of collector openings 46. The emulsion inlet 42, and the oil and water outlets 47 and 48, may carry the customary valves for regulating the flows of liquid into and out of the vessel 11. For example, the water outlet 48 may be controlled in the rate of water withdrawal by a float device for maintaining the interface 50 at a desired horizon. In addition, the oil outlet 47 may contain a backpressure valve to maintain liquids in a liquid phase within the vessel 11. These valves elements are conventional and therefore are not shown in the drawings.

The conduit 39, provides in a novel treater structure, a gravity-liquid, heat barrier in the liquid extending from within the vessel 11 to the electrical bushing 37. More particularly, this barrier or thermal dam, formed in the conduit 39 provides a dynamic barrier which prevents cooler liquid surrounding the bushing 37 from circulating and intermingling with the heated liquid in the vessel 11 although the same liquid extends throughout the conduit 39. With this arrangement, only that liquid immediately surrounding the electrical bushing 37 is adjusted in temperature so that a temperature gradient is maintained in the liquid between the bushing 37 and the interior of the vessel 11, which gradient is favorable to the extended operation of the electrical bushing 37.

The conduit 39 may take any one of various arrangements as can be seen from the drawings. However, in the arrangement of FIG. 1, the conduit 39 is formed of uniform-diameter, rigid tubing. The conduit 39 is secured at one end to flanged nozzle 52 carried on top of the vessel 11. A flange plate 54 having a central threaded opening to receive the electrode bushing 37 is secured to a flange at the closed end 53 of the conduit 39. Thus, the entrance bushing 37 is in free liquid communication with the interior of the vessel ll.

The conduit 39 has an upwardly extending portion 56 immediately above the nozzle 52. Secured to the upper extremity of the portion 56 is an intermediate bight portion 57 which forms the thermal dam in this embodiment of the present system. A downwardly extending portion 58 extends from the bight portion 57 and ultimately connects to the closed end 53. The downwardly extending portion 58 of the conduit 39 may be in any orientation other than upward or horizontal. The portion must extend downwardly below the lower terminus of the bight portion 57. For this purpose, the angle formed between the portions 56 and 58 should be, at their connections to the bight portion 57, less than and greater than 270 relative to a vertical line passing through the adjacent terminus of the upwardly extending portion 56. Preferably the portions 56 and 58 are in parallel, spaced-apart alignment.

Heat exchanger means 59 are associated with the portion 58 and these means preferably extend from the bight portion 57 to the closed end 53. The heat exchanger means may take any form, as for example, plain or finned air cooling surfaces on the conduit 39. In certain circumstances, it may be preferred to provide a helical cooling coil 60 surrounding the portion from 500 F. to ambient temperature (e.g., F.).

With the present arrangement of the conduit 39, the bight portion 57 provides the gravity-liquid heat barrier, or thermal dam, to prevent the heated liquid in the vessel 111 from circulating through the conduit 39 to intermix with the cooler liquid in portion 58 surrounding the electrical bushing 37. The heated liquid from the vessel 11 passes upwardly in a circulating flow through the conduit 39 until it traverses the bight portion 57 and starts to enter the downwardly extending portion 58. The downwardly extending portion 58 projects at a downward angle from the bight portion 57. The cooler liquid surrounding the bushing 37 is prevented by the specific gravity differential between the heated and cooled liquids from a circulation to intermix with the heated liquid in the bight portion 57. The cooler liquid seeks only to move downwardly into the portion 58. The heated liquid seeks only to move upwardly into the bight portion 57. Thus, a thermal dam is formed at the hot-cold liquid interface at the bight portion which, for all practical purposes, prevents any significant intermingling of the heated and cooled liquids. The only significant transfer of heat energy is by conduction across the heat barrier and this amount is relatively small. It is advantageous in some installations to enhance the thermal dam effect, to prevent excessive heat losses of the liquid in the vessel 11, and for other reasons, to insulate the conduit 39 through the portions 56 and 57. For example, the liquid within the bight 57 may be at a temperature of 350 F. whereas the temperature in the liquid within the lower portion 58 at the entrance bushing 37 may be maintained at 98 F. without any substantial amount of cooling provided by the heat exchanger means 59 other than to compensate for the slight conduction heating effect.

The system of the present invention was tested in an experimental conduit arrangement constructed to thermodynamically resemble FIG. 1. The test system will be described as a modification of FIG. I. The conduit 39 was formed of 8 inch, schedule 40 steel pipe. The vertical portion 56, of 4 feet length, was closed at its lower extremity and placed within an insulated housing which contained a gas burner immediately below the closed end of the pipe. The burner represented the heat source of the vessel 11. The bight 57 of 180 return bends was insulated with one inch thick fiberglass insulation having an aluminum foil backing. The lower vertical extending portion 58 was uninsulated for air cooling and extended below the bight 57 for a distance of 3 feet. The bight portion in the experimental arrangement was considered to terminate where the 180 bend tubing changed from a curved surface into the vertical downwardly extending portion of the portion 58. The flange 54 was sealed with a reducer bushing containing a valved oil drain. A relief oil port was installed in the upper extremity of the bight 57 to permit an expansion of the transformer oil which completely filled the conduit 39. Thermal couples were placed at the top of the bight 57 and along the portion 58 at one foot intervals above the closed end 53. The burner was ignited and regulated until the temperature of the transformer oil reached an equilibrium condition. The temperatures were raised in the transformer oil within the bight 57 until it reached an equilibrium at 354 F. The lower downwardly extending portion 58 was cooled by ambient surrounding air having a temperature between 75 and 85 F. The following temperatures were noted on thermal couples beginning at the closed end of the portion 58. The closed end was at a temperature of 98 F., and at l, 2 and 3 feet above the closed end, the temperatures were, respectively, 100 F., 1 10 F., and 175 F. These equilibrium temperatures were maintained with nearly exact preciseness for over one hour of equilibrium time. The interface between the heated cooled liquid remained at a relatively constant horizon and was of a vertical dimension of only a few inches. Calculations indicate that about 900 BTUs per hour were transferred into the liquid in the portion 58. Thus, air cooling was a satisfactory heat exchange means to maintain the temperatures of about 100 F at the closed end of the portion 58. The experimental data and calculations clearly indicates the satisfactory operation of the gravity-liquid heat barrier provided by the bight portion 57 in the present arrangement.

The above test was repeated but with the portion 58 arranged first horizontally and then vertically oriented from the bight portion 57. With the portion 58 extending horizontally from the bight portion 57, the temperatures at all the thermal couples varied only between 330 and 310 F. The slow rise of the temperatures in the portion 58 was such that after an extended time of heating, it appeared that all the thermal couples would reach approximately a temperature of about 330 F.

With the portion 58 extending vertically from the bight portion 57 (by severing the bight portion 57 at its mid-point and then reorienting one 90 turn upwardly, the now upwardly extending portion 58 had equilibrium temperatures which resided between 340 and 330 F. r

The above tests indicate that the portion 58 must extend downwardly below the lower terminus of the bight portion 57 when the temperature of the liquid in the vessel 11 is higher than the temperature of the liquid surrounding the bushing 37.

In the present arrangement of FIG. 1, the conduit 39, is formed of rigid tubing, preferably of a uniform diameter. However, the conduit 39 does not need to be formed of one-piece or uniform diameter tubing for operation of the present system. FIGS. 2, and 3 show other embodiments of the present system which can employ advantageously flange connections and the like between conduit segments.

Referring now to FIG. 2 of the drawings, there is shown another embodiment of the system of the present invention in an enlarged partial section wherein like parts between the FIGS. 1 and 2 carry like numeral designations for convenience in description. The interior details of the vessel 11, distributor, electrodes and insulation are omitted to simplify the description. However, it is understood that the arrangements of the electrodes, distributors, insulators, etc. may be the same or different from that shown in FIG. 1 without concerning the proper element functioning of the structure shown in FIG. 2.

The nozzle 52 of the vessel 11 is secured to a conduit 61 which extends from the vessel 11 to a closed end 62 carrying a flange plate 63 with an aperture to receive an entrance bushing 64. The entrance bushing 64 is in direct liquid communication with the interior of the vessel 11. The entrance bushing 64 is connected by a conductor 65 to an external source of power (not shown) which may be a power transformer.

An electrical conductor 66 extends from the entrance bushing 64 into the vessel 11 and connects to an energized electrode therein. The electrical conductor 66 can be formed of a rigid rod or tubing and carries a flange connection 67 and an elbow connector 68 at its ends. The elbow 68 carries a rod connection 69 that interconnects by a flexible lead 71 to the lower electrical terminal of the bushing 64. With this arrangement, the conductor 66 adjacent the closed end 62 of the conduit 61 is free to move within certain limits provided by the flexible lead 71 to avoid mechanical injury to the bushing 64.

The electrical conductor 66 is carried on a cantilever mounting within the vessel 11. The cantilever mounting is comprised of a pair of angle-iron supports 72 and 73 forming a box-like arrangement which has its lower extremity formed by members 74. The members 74 form a horizontal platform supporting a short insulator pipe 76 upon which a flange-like metal disc 77 is mounted. The supporting member 72 and 73 are secured to the upper surface of the vessel 11 by any suitable means, such as by welding. The pipe 76 is fabricated from a dielectric material, such as Teflon plastic material. A spool piece 78 has a flanged interconnection with the flange 67 on the conductor 66. The spool 78 carries a flange 79 secured to the disc 77 with a central rod 81 extending downwardly for electrical connection to the energized electrode by a flexible lead 82.

A cantilever arm 83 is secured horizontally to the disc 77 and carries a laterally adjustable weight 84 to eliminate any bending moment. The conductor 66 is supported with its entire weight upon the disc 77 and adjustment of the cantilever weight 84 on the arm 83 orients the conductor 66 into coaxial alignment within the conduit 66. Thus, the flexible lead 71 does not have to support the end of the conductor 66 to maintain proper coaxial alignment within the conduit 61.

The conduit 61 has the same components of the conduit 39 in MG. 1 but it also contains additional advantageous structural features. More particularly, the conduit 61 has an upright portion 86, an intermediate bight portion 87, a first downwardly extending portion 88, a second intermediate bight portion 89 and second upwardly extending portion 91. It is preferred that the portions 87 and 89 interconnect the vertical aligned portions 86 and 88 with 180 return bends. Thus, the two portions 86 and 88 are arranged in paralled but spaced apart relationship. The portions 86 and 87 may be insulated and air-cooling heat exchanger means are associated with the portion 88. The bight portion 87 serves the function of the thermal dam as was described for the earlier embodiment.

The conduit 61 is filled in its entirety with a dielectric liquid which may be the liquid treated within the vessel 11. Initially, portions 88, 89 and 91 may be filled with transformer oil. A valved vent line 92 at the upper extremity of the bight 8'7 permits the venting of all gases from the conduit 61 to avoid corona discharges (arcs). A second valved vent line 93 in the lowermost part of the portion 89 permits removal of any accumulating water or other settleable deleterious materials within the conduit 61. In the event than any gasses collect during installation or operation within the upwardly extending portion 91 of the conduit 61, a valved vent line 97 provides for removal of the gas phase. The dielectric liquid filling the conduit 61 should remain relatively uncontaminated by gas or water to the extent that electrical leakage or arcing injure the insulating properties of the entrance bushing 64.

The heated liquid in the vessel 11 rises through circulating flows with the liquid in the portions 86 and 87 until it reaches the first downwardly extending portion 88. At this location, there is formed an interface between the heated liquid rising from the vessel 11 and the static-contained liquid in the portions 88, 89 and 91. The heat exchange means associated with the portion 88 may be provided by air cooling simply by leaving that portion of the conduit 61 uninsulated for a sufficient dimension to remove the heat entering the cold liquid. If desired, the portions of the conduit namely 86 and 87 also may be left uninsulated. However, for practical purposes these portions are insulated to reduce the heat losses of liquid within the vessel 11.

In order to facilitate arrangement of the connection between the conductor 66 and the entrance bushing 64, the bight portion 89 and the upwardly extending portion 91 are formed by a pipe tee 90. The tee 90 carries a flange 94 connected to an imperforate cover 96 by bolts, or other releasable mounts. The cover 96 is removed to permit connection of the flexible lead 71 on rod 69 to the lower extremity of the entrance bushing 64. The conduit 61 is formed by a rigid tubing of uniform diameter interconnected between the nozzle 52 and the tee 90 forming the bight portion 89 and portion 91. However, the tubing need not be of uniform diameter nor as a continuous loop through the portions 86, 87 and 88. For example, these portions may be interconnected through the use of standard pipe tees and flanged connections as in the embodiment illustrated in FIG. 3.

In FIG. 3, the arrangement of the electric treater in the present system may be as is shown in FIG. 1, and therefore, like parts bear like numerals for convenience in description. The interior details of the vessel 11, including distributor and insulation are omitted to simplify the description except for a schematic view of electrodes 13 and 24. Secured atop the vessel 11 on the nozzle 52 is a conduit 101 which extends to a closed end 102. The closed end 102 carries an apertured flange 103 in which is received an entrance bushing 104. Thus, the entrance bushing 104 is in direct liquid communication with the interior of the vessel 11. An electrical conductor 106 extends coaxially through the conduit 101 from the entrance bushing 104 into electrical contact with the energized electrode 24 within the vessel 11. The electrical conductor 106 at one end is connected by a flexible lead 107 to the lower portion of the bushing 104.

The conductor 106 rests directly in a metal structure 108 bolted to the energized electrode 24. The structure 104 has an apertured alignment ring 109 carried upon legs 111. The legs 111 secure to a base plate ring 112 bolted to the energized electrode 24. The conductor 106 is secured to a tee connector 113 from which depends a lower connection rod 114 traversing an opening in the grounded electrode 13. The rod 1 14 passes in a loose fit through the ring 109 to rest upon the base ring 112. Thus, the electrical conductor 106 may move vertically with several inches of movement but can not be displaced in the horizontal. A cantilever arm 116 is connected to the tee 113 and carries an adjustable weight 117. Adjustment of the cantilever weight 117 provides for coaxially positioning the conductor 106 within the conduit 101. The cantilever mounting balances the rod 114 and removes, for all practical purposes, any weight support requirements by the bushing 104.

The conduit 101 is formed of a rigid tubing which preferably has a uniform diameter and is readily constructed from an arrangement of pipes and conventional tee fittings. More particularly, the conduit 101 is formed of a first upward extending portion 121 connected to a first bight portion 122. The portion 122 may be readily formed by connection together the branch or side openings of two pipe tees with one of the lower aligned portions connected to the portion 121. The second aligned opening connects to a first downwardly extending portion 123. The other ends of the aligned openings on the tees carry flanges 124 and 126. The flanges 124 and 126 are covered by liquidtight plates 127 and 128 which maybe secured in-place by bolting. The downwardly extending portion 123 connects to a second bight portion 129 which may be formed of a pipe tee in the same manner as was discussed for the bight portion 89 of FIG. 2. The second bight portion 129 carries a flange 131 which is closed by a liquid-tight cover 132 by bolting. Removal of the cover 132 permits ready access for connection of the flexible braid 107 to the lower portion of the bushing 104.

The conduit 101 from the portion 123 to the end 102 is associated with heat exchanger means. The heated liquid from the vessel 11 circulates readily upwardly in the conduit 101 until reaching the bight portion 122 in the region of the downward deflection in the downwardly extending portion 123. At the merger in the conduit 101 between the bight portion 122 and the downwardly extending portion 123, the heated and cool liquids form a heat-barrier interface or thermal dam. More particularly, the heated liquid is of a lesser specific gravity than the cold liquid in the portion 123. Since the interface between these two differential temperature liquids is horizontal and bounded by imperforate upright walls, a circulating flow of hot liquid can not mix with the cooler liquid and thereby transfer heat by convention downwardly in the portion 123. Thus, the gravity-liquid heat barrier of the present system limits heat transfer to conduction across the interface of the thermal dam.

To simplify construction and installation of the electrical conductor 106 in this embodiment, standard pipe fittings may be employed. For this purpose, the conductor 106 is formed of a first section of pipe extending upwardly from the tee 113 into a second tee 133. The tee 133 carries a short horizontal section of piping 134 which connects into a floor plate 136. The plate 136 connects through a flange 137 to a vertical section of pipe 138. The pipe 138 at its lower extremity connects to an elbow 139 which carries a rod 141 terminating with a connection to the flexible lead 107.

The conductor 106 may be coaxially aligned within the top parts of conduit 121 by a stud 142 carried within a bushing threaded into the tee 133. The upper terminal of the stud 142 is threaded into an insulator 143 secured into a floor plate 144 beneath the flange 127 by bolts 146. The insulator 143 does not support any appreciable weight of the electrical conductor 106. Rather,the function of the insulator 143 is merely to provide an upper steadying rest for the conductor 106. The cantilever arrangement at the lower portion of the electrical conductor 106 can maintain the desired coaxial alignment thoughout the conduit 101, if desired.

The upper extremity of the bushing 104 may be connected to a source of electrical power by the structures shown in FIG. 1. However, the bushing 104 and power source can be connected by the same arrangement shown in U.S. Pat. No. 3,303,262. For this purpose, the flange 103 carries a tee connection 151 which has a side opening connected through an interconnecting conduit 152 to the transformer case 153. A second bushing 154 receives power from the transformer and extends through the case 153 of the transformer and connects to the bushing 104 by a lead 156. The conduit interconnection between the bushings 104 and 154 is completely filled with transformer oil, or other dielectric material, and secured by a cover 157 secured to the flange 158 carried upon the tee 151.

The conduit 101 carries a top valved vent line 161 and a lower valved vent line 162. Trapped gas may be removed by line 161 from the upper extremities of the conduit 101, and any settled water or other deleterious sediment may be removed through the line 162.

The present embodiments have been described in constructions for use specifically where the temperature of the liquid within the vessel 11 is greatly above the temperature of the liquid surrounding the electrical bushing. However, the present system will operate in the reverse manner. For example, the vessel 11 may be filled with cryogenic liquid and the first downwardly extending portion may be associated with heat exchanger means which heat the liquid surrounding the electrical bushing. Thus, the electrical bushing is maintained by the heat exchanger means at a temperature gradient favorable to its operation compared to the temperature of the liquid within the vessel 1 1.

It will be apparent that only a first bight portion must connect the upright portion of the conduit on the vessel 1 1 with a downwardly extending portion that eventually is connected to the closed end of such conduit. It is immaterial how many subsequent bight portions, vertical portions and downwardly extending portions are intermediate such first downwardly extending portion and the closed end of the electrical conduit. There may be one or more of such arrangements as will be apparent from consideration of Figures of the drawings.

From the foregoing, it will be apparent that there has been provided a system for electrical resolution of emulsions which is well adapted to satisfy the purposes of the present invention. Various changes may be made to the system without departing from the spirit of this invention. The foregoing description is to be taken as illustrative of the present invention.

What is claimed is:

l. A system for electrically treating an oil-continuous emulsion containing dispersed phase contaminating substances comprising:

a. a vessel;

b. said vessel containing inlet and outlet means for passing fluids through said vessel;

c. electrode means connectable to a source of electrical potential for creating an electric field within said vessel;

. a source of electrical potential external of said vessel;

e. a conduit extending from said vessel to a closed end containing an entrance bushing connected to said source of electrical potential, and said bushing being in fluid communication through said conduit with the interior of said vessel;

f. an electrical conductor extending in electrical isolation within said conduit from said entrance bushing to said electrode means;

g. said conduit containing an upwardly extending portion adjacent said vessel, an intermediate bight portion, and a downwardly extending portion between said bight portion and said closed end containing said entrance bushing; and

h. heat exchanger means associated with said downwardly extending portion of said conduit for creating a temperature gradient between said entrance bushing and the interior of said vessel.

2. The system of claim 1 wherein said conduit contains an upright portion adjacent said vessel, an intermediate bight portion with an 180 return bend forming the thermal dam and a vertical portion extending downwardly from said bight portion.

3. The system of claim 1 wherein said bight portion of said conduit has a bend less than and greater than 270 relative to a vertical line passing through the adjacent terminus of said upwardly extending portion.

4. The system of claim 1 wherein said downwardly ending portion connects by a second bight portion to a second upwardly extending portion which terminates with a closed end containing said entrance bushing.

5. The system of claim 1 wherein said heat exchanger means provides a temperature gradient at said bushing more favorable to its operation than the temperature within said vessel during electrical treatment of the emulsion.

6. A system for electrically treating an oil-continuous emulsion containing dispersed phase contaminating substances comprising:

a. a vessel;

b. said vessel containing inlet and outlet means for passingfluids through said vessel;

0. electrode means connectable to a source of electrical potential for creating an electric field within said vessel;

d. a source of electrical potential external of said vessel;

e. a conduit extending from said vessel to a closed end containing an entrance bushing connected to said source of electrical potential, and said bushing being in fluid communication through said conduit with the interior of said vessel;

f. an electrical conductor extending in electrical isolation within said conduit from said entrance bushing to said electrode means;

g. said conduit formed of rigid tubing, and said conduit containing a first upwardly extending portion releasably secured at one end to said vessel, a first intermediate bight portion with an 180 return bend forming a thermal dam, a first downwardly extending portion adjacent said first bight portion, a second intermediate bight portion with an 180 return bend forming a second thermal dam and a second upwardly extending portion between said second bight portion and said closed end containing said entrance bushing;

h. said electrical conductor formed of rigid electrical conductive material and supported concentrically and in electrical isolation from said conduit at one end by insulator means mounted within said vessel and at the other end of said conduit by being secured to said entrance bushing; and

i. heat exchanger means 7 associated with said downwardly extending portion of said conduit for creating a temperature gradient between said entrance bushing and the interior of said vessel.

7. The system of claim 6 wherein said electrical conductor is supported in cantilever from saidinsulator means in said vessel.

8. The system of claim 6 wherein said first and second bight portions contain valve means whereby fluid may be selectively removed from said conduit.

9. The system of claim 6 wherein said second upwardly extending portion of said conduit adjacent said closed end containing said entrance bushing contains valve means at an upper horizon whereby fluid may be selectively removed from said conduit.

10. The system of claim 6 wherein said first and second upwardly extending portions are oriented in the vertical.

11. The system of claim 7 wherein said insulator means comprise a supporting rack secured to said vessel, aninsulator carried by said rack and one end of said electricalconductor secured to said insulator in electrical isolation to said rack.

12. The system of claim 7 wherein a counter weight is carried on said electrical conductor within said vessel for balancing the parts of said electrical conductor which extend through said conduit whereby said entrance bushing carries no significant weight of said electrical conductor.

13. The system of claim 7 wherein a flexible braid interconnects the end of said electrical conductor within said vessel to said electrode means.

14. A system for electrically treating an oil-continuous emulsion containing dispersed phase contaminating substances comprising:

a. a vessel;

b. said vessel containing inlet and outlet means for passing fluids through said vessel;

c. electrode means connectable to a source of electrical potential for creating an electric field within said vessel;

. a source of electrical potential external of said vessel;

e. a conduit extending from said vessel to a closed end containing an entrance bushing connected to said source of electrical potential, and said bushing being in fluid communication through said conduit with the interior of said vessel;

f. an electrical conductor extending in electrical isolation within said conduit from said entrance bushing to said electrode means; I

g. said conduit formed of rigid tubing, and said conduit containing a first upwardly extending portion releasably secured at one end to said vessel, a first intermediate bight portion with an return bend forming a thermal dam, a first downwardly extending portion adjacent said first bight portion,

a second intermediate bight portion with an 180 return bend forming a second thermal dam and a.

second upwardly extending portion extending between said second bight portion and said closed end containing said entrance bushing;

said first intermediate bight portion formed by interconnecting together the side openings of two tees and the lower aligned openings to the first upwardly and downwardly extending portions, and the upper aligned openings of said tees being sealed by fluid tight closure members;

. said electrical conductor formed of rigid electrical conductive material supported concentrically and in electrical isolation from said conduit, said conductor supported substantially in its entire weight by an insulator carried in one of the upper aligned openings of said tees forming said bight portion, a flexible braid connecting one end of said conductor to said entrance bushing, a second flexible braid connecting the other end of said conductor to said electrode means within said vessel, and an alignment support carried on said electrode means to position the lower extremity of said conductor within a limited horizontal area while permitting relatively free vertical movement of said conductor relative to said vessel, and a counterweight carried on said conductor within said vessel for balancing the parts of said conductor which extend through said conduit about the support provided by said insulator carried by said bight portion whereby said entrance bushing carries no significant weight of said conductor; and

i. heat exchanger means associated with said downwardly extending portion of said conduit for creating a temperature gradient between said entrance bushing and the interior of said vessel.

15. The system of claim 14 wherein said first and second bight portions contain valve means whereby fluid may be selectively removed from said conduit.

16. The system of claim 14 wherein said first and second upwardly extending portions are oriented in the vertical.

UNITED STATES PATENT oFFIcE CERTIFICATE OF CORRECTION Patent N 3. 7l9.584 Dated March 6, 1973 Inventor(s) Delber w. Turner It is certified that error appears in the above-identified patent and that said Lett'ers Patent are hereby corrected as shown below:

Column 3, line 21 for "heater" read -treater---; I line 40, after "'closed end" insert --.and--; and

lines 49-50, cancel "containing" and substitute therefore -and--;

Column 5 line 64, for "electrode", read --eleci;rical -v;

Column 9, line 30 for "than" read ---that--; and for "gasses", read I v-- gases Column ll line 40, for "thoughout" read ---throughout---;

Claim 1 Column 12 line 41 after "end" insert ---andand 1 line 52, cancel "containing" and substitute therefor and Cl aim 2 Column 12, ,line 61, cancel "the" and substi tute. therefor ---a--;

Claim 6 Column 13, line 230 after "end" insert ---andand,

, lines 37-38, cancel "containing" and substitute therefor Claim 9 Column 13, line 57 after "end" insert -ahdand Cl aim l4, Column 14', line 22, after end" insert ---and---; and

line 40, cancel "containing" andsubstitute therefor ---and---. a

Signed and sealed this 20th day of November 1973 I (SEAL) Attest:

EDWARD M.FLE'ICHER,JR. RENE ,D. TEGTMEYER Attesting Officer I 1 Acting Commissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 719,5 4 Dated March 6 1973 Inventor(s) Delber w. Turner- It: is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 2l for "heater" read -treater---; 7

line 40, after "'closed end" inser't ---and---; and lines 49-50, cancel "containing" and substitute therefore ---and- Column 5 line 64, for "electrode" read -electrical Column 9, line 30 for "than" read ---that--; and for "gasses" read i gases Column ll line 40, for "thoughout", read ---throughout---;

Cl aim l Column l2 line 41 after "end" insert ---and---, and

line 52,, cancel "containing" and substitute therefor and Claim 2, Column T2, line 61, cancel "the" and substitute. therefor --a--;

Cl aim 6 Column 13, line 20 after "end" insert ---andand lines 37-38, cancel "containing" and substitute therefor ---and-*-; i i

Claim 9, Column 13, line 57, after "end", insert ---ahd---; and

Claim 14, Column l4,line 22, after "end", insert ---and---; and

line 40, cancel "containing" and substitute therefor ---and---.

Signed and sealed this 20th day of November 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR, RENE .D. TEGTMEYER Attesting Officer Acting Commissioner of Pateni 

1. A system for electrically treating an oil-continuous emulsion containing dispersed phase contaminating substances comprising: a. a vessel; b. said vessel containing inlet and outlet means for passing fluids through said vessel; c. electrode means connectable to a source of electrical potential for creating an electric field within said vessel; d. a source of electrical potential external of said vessel; e. a conduit extending from said vessel to a closed end containing an entrance bushing connected to said source of electrical potential, and said bushing being in fluid communication through said conduit with the interior of said vessel; f. an electrical conductor extending in electrical isolation within said conduit from said entrance bushing to said electrode means; g. said conduit containing an upwardly extending portion adjacent said vessel, an intermediate bight portion, and a downwardly extending portion between said bight portion and said closed end containing said entrance bushing; and h. heat exchanger means associated with said downwardly extending portion of said conduit for creating a temperature gradient between said entrance bushing and the interior of said vessel.
 1. A system for electrically treating an oil-continuous emulsion containing dispersed phase contaminating substances comprising: a. a vessel; b. said vessel containing inlet and outlet means for passing fluids through said vessel; c. electrode means connectable to a source of electrical potential for creating an electric field within said vessel; d. a source of electrical potential external of said vessel; e. a conduit extending from said vessel to a closed end containing an entrance bushing connected to said source of electrical potential, and said bushing being in fluid communication through said conduit with the interior of said vessel; f. an electrical conductor extending in electrical isolation within said conduit from said entrance bushing to said electrode means; g. said conduit containing an upwardly extending portion adjacent said vessel, an intermediate bight portion, and a downwardly extending portion between said bight portion and said closed end containing said entrance bushing; and h. heat exchanger means associated with said downwardly extending portion of said conduit for creating a temperature gradient between said entrance bushing and the interior of said vessel.
 2. The system of claim 1 wherein said conduit contains an upright portion adjacent said vessel, an intermediate bight portion with an 180* return bend forming the thermal dam and a vertical portion extending downwardly from said bight portion.
 3. The system of claim 1 wherein said bight portion of said conduit has a bend less than 90* and greater than 270* relative to a vertical line passing through the adjacent terminus of said upwardly extending portion.
 4. The system of claim 1 wherein said downwardly ending portion connects by a second bight portion to a second upwardly extending portion which terminates with a closed end containing said entrance bushing.
 5. The system of claim 1 wherein said heat exchanger means provides a temperature gradient at said bushing more favorable to its operation than the temperature within said vessel during electrical treatment of the emulsion.
 6. A system for electrically treating an oil-continuous emulsion containing dispersed phase contaminating substances comprising: a. a vessel; b. said vessel containing inlet and outlet means for passing fluids through said vessel; c. electrode means connectable to a source of electrical potential for creating an electric field within said vessel; d. a source of electrical potential external of said vessel; e. a conduit extending from said vessel to a closed end containing an entrance bushing connected to said sOurce of electrical potential, and said bushing being in fluid communication through said conduit with the interior of said vessel; f. an electrical conductor extending in electrical isolation within said conduit from said entrance bushing to said electrode means; g. said conduit formed of rigid tubing, and said conduit containing a first upwardly extending portion releasably secured at one end to said vessel, a first intermediate bight portion with an 180* return bend forming a thermal dam, a first downwardly extending portion adjacent said first bight portion, a second intermediate bight portion with an 180* return bend forming a second thermal dam and a second upwardly extending portion between said second bight portion and said closed end containing said entrance bushing; h. said electrical conductor formed of rigid electrical conductive material and supported concentrically and in electrical isolation from said conduit at one end by insulator means mounted within said vessel and at the other end of said conduit by being secured to said entrance bushing; and i. heat exchanger means associated with said downwardly extending portion of said conduit for creating a temperature gradient between said entrance bushing and the interior of said vessel.
 7. The system of claim 6 wherein said electrical conductor is supported in cantilever from said insulator means in said vessel.
 8. The system of claim 6 wherein said first and second bight portions contain valve means whereby fluid may be selectively removed from said conduit.
 9. The system of claim 6 wherein said second upwardly extending portion of said conduit adjacent said closed end containing said entrance bushing contains valve means at an upper horizon whereby fluid may be selectively removed from said conduit.
 10. The system of claim 6 wherein said first and second upwardly extending portions are oriented in the vertical.
 11. The system of claim 7 wherein said insulator means comprise a supporting rack secured to said vessel, an insulator carried by said rack and one end of said electrical conductor secured to said insulator in electrical isolation to said rack.
 12. The system of claim 7 wherein a counter weight is carried on said electrical conductor within said vessel for balancing the parts of said electrical conductor which extend through said conduit whereby said entrance bushing carries no significant weight of said electrical conductor.
 13. The system of claim 7 wherein a flexible braid interconnects the end of said electrical conductor within said vessel to said electrode means.
 14. A system for electrically treating an oil-continuous emulsion containing dispersed phase contaminating substances comprising: a. a vessel; b. said vessel containing inlet and outlet means for passing fluids through said vessel; c. electrode means connectable to a source of electrical potential for creating an electric field within said vessel; d. a source of electrical potential external of said vessel; e. a conduit extending from said vessel to a closed end containing an entrance bushing connected to said source of electrical potential, and said bushing being in fluid communication through said conduit with the interior of said vessel; f. an electrical conductor extending in electrical isolation within said conduit from said entrance bushing to said electrode means; g. said conduit formed of rigid tubing, and said conduit containing a first upwardly extending portion releasably secured at one end to said vessel, a first intermediate bight portion with an 180* return bend forming a thermal dam, a first downwardly extending portion adjacent said first bight portion, a second intermediate bight portion with an 180* return bend forming a second thermal dam and a second upwardly extending portion extending between said second bight portion and said closed end containing said entrance bushing; said first intermediatE bight portion formed by interconnecting together the side openings of two tees and the lower aligned openings to the first upwardly and downwardly extending portions, and the upper aligned openings of said tees being sealed by fluid tight closure members; h. said electrical conductor formed of rigid electrical conductive material supported concentrically and in electrical isolation from said conduit, said conductor supported substantially in its entire weight by an insulator carried in one of the upper aligned openings of said tees forming said bight portion, a flexible braid connecting one end of said conductor to said entrance bushing, a second flexible braid connecting the other end of said conductor to said electrode means within said vessel, and an alignment support carried on said electrode means to position the lower extremity of said conductor within a limited horizontal area while permitting relatively free vertical movement of said conductor relative to said vessel, and a counterweight carried on said conductor within said vessel for balancing the parts of said conductor which extend through said conduit about the support provided by said insulator carried by said bight portion whereby said entrance bushing carries no significant weight of said conductor; and i. heat exchanger means associated with said downwardly extending portion of said conduit for creating a temperature gradient between said entrance bushing and the interior of said vessel.
 15. The system of claim 14 wherein said first and second bight portions contain valve means whereby fluid may be selectively removed from said conduit.
 16. The system of claim 14 wherein said first and second upwardly extending portions are oriented in the vertical.
 17. The system of claim 14 wherein one said upper aligned opening on said tees forming said first bight portion is releasably secured by a covering flange. 